The present invention relates to audio signal processing, and more specifically to a method and system for adapting a clock frequency based on parameters of incoming signals for the audio applications.
Today's digital hearing aids are typically constrained in terms of how much current the audio processing engine(s) and transducers can consume due to small energy constrained batteries being used to power the hearing aids. It is the objective of the hearing aid designer to design the audio processing scheme embedded in the hearing aid in such a way that the overall current consumption is minimized. Lower current typically results in longer battery life, which is of benefit for the hearing aid end user. Longer battery life means that batteries will not have to be changed as often, which leads to cost savings and less inconvenience for the end-user.
Hearing aids typically have one or more programmable and/or configurable audio processing engines, in which the audio signal is processed digitally to provide signal enhancements for the hearing impaired user. These audio processing engines typically operate at a fixed clock frequency that is determined by the frequency of a main oscillator or a divided frequency of the main oscillator frequency. A fixed oscillator frequency being used for a processing engine implies that the engine will be running at a fixed frequency regardless of the amount of processing that the engine performs.
However, typically the amount of processing required depends on the nature of the parameters of the signal that the engine processes. In one scenario the nature of the parameters may require less cycles of processing within a set time period compared to what is made available by the main oscillator. Likewise, in another scenario the parameters of the signal may require more cycles of additional processing within a set time period compared to what is made available by the main oscillator.
In the first scenario the need for only a few cycles of processing compared to overall cycles available within a given time period implies that the frequency of clock cycles required is lower than the actual frequency of clock cycles provided by the main oscillator.
Similarly, in the second scenario the need for more clock cycles of processing compared to overall cycles available within a given time period implies that the frequency of clock cycles required is higher than the actual frequency of clock cycles provided by the main oscillator.
The fact that the clock frequency cannot be adjusted adaptively based on the nature of the signal parameters means that in the case where few cycles are required for processing compared to overall available cycles there will be unused cycles available for additional processing. Unused cycles implicitly mean that the clock frequency is too high for the actual processing required. In turn, too high a frequency implies that current from the battery is being consumed un-necessarily, which again leads to reduced battery life time.
Similarly, the fact that the clock frequency cannot be adjusted adaptively based on the nature of the signal parameters means that in the case where higher number of cycles are required compared to overall available cycles there will not be enough cycles available for additional processing. This implicitly means that the clock frequency is too low for the actual processing required.
There is a need for a system that allows for clock frequency adjustments in a digital hearing aid through adaptive change of the clock frequency to one or more processing engines.